A system for dispensing a sample into a buffer liquid includes a pressure chamber having pressure supply means for generating an overpressure within the pressure chamber. An inlet capillary supplies a buffer liquid to an outlet end arranged in the pressure chamber, and an outlet capillary discharges the buffer liquid from the pressure chamber. The outlet capillary has an inlet end in the pressure chamber facing the outlet end of the inlet capillary to form a capillary gap. A dispenser having a dispensing end is in the pressure chamber at the capillary gap to allow the sample at the dispensing end to be dispensed into the buffer liquid entering the outlet capillary inlet end. The pressure chamber includes a sample port that allows the dispenser to be moved into and out of the pressure chamber.